/* global.c -- uses an external variable */
#include <stdio.h>
int units = 0; /* an external variable         */
void critic(void);
int main(void) {
  extern int units; /* an optional redeclaration    */

  printf("How many pounds to a firkin of butter?\n");
  scanf("%d", &units);
  while (units != 56) critic();
  printf("You must have looked it up!\n");

  return 0;
}

void critic(void) {
  /* optional redeclaration omitted */
  printf("No luck, my friend. Try again.\n");
  scanf("%d", &units);
}
